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The present research article introduces a novel, environmentally friendly method for synthesizing ironoxide nanoparticles (IONPs) utilizing Callistemon viminalis flowers extract as both a reducing and capping agent. This approach not only offers a sustainable and cost-effective alternative to conventional synthesis methods but also harnesses the inherent phytochemical potential of the plant extract. The synthesized IONPs underwent comprehensive characterization using various analytical techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and dynamic light scattering (DLS) to elucidate their structural, morphological, and chemical properties. Subsequently, the synthesized IONPs were evaluated for their potential antioxidant properties. The research findings contribute valuable insights into the synthesis process, structural characteristics, and antioxidant efficacy of the synthesized nanoparticles, offering promising avenues for addressing both health and environmental challenges with innovative solutions.

In the current study, the bottlebrush [Callistemon viminalis (Sol. ex Gaertn.) G. Don] plant was selected for the green synthesis of silver (Ag) and gold (Au) nanoparticles and to evaluate its antibacterial and antifungal activities. Phytochemical screening of C. viminalis confirmed the presence of alkaloids, anthraquinones, saponins, tannins, betacyanins, phlobatanins, coumarins, terpenoids, steroids, glycosides, and proteins. To characterize the synthesized Ag and Au NPs, UV–Visible spectroscopy, FTIR spectroscopy for functional group identification, field emission scanning electron microscopy (FE-SEM) for particle size, and elemental analysis were performed using EDX. The UV–Visible absorption spectra of the green-synthesized Ag and Au nanoparticles were found to have a maximum absorption band at 420 nm for Ag NPs and 525 nm for Au NPs. FE-SEM analysis of the synthesized NPs revealed a circular shape with a size of 100 nm. Elemental analysis was performed for the synthesis of Ag and Au NPs, which confirmed the purity of the nanoparticles. The greenly synthesized Ag and Au NPs were also evaluated for their anti-bacterial and anti-fungal activities, which exhibited prominent inhibition activities against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Candida albicans, C. krusei, Aspergillus sp., and Trichoderma species. The highest zone of inhibition 15.5 ± 0.75 and 15 ± 0.85 mm was observed for Ag NPs against E. coli and P. aeruginosa. Similarly, Trichoderma sp. and Aspergillus sp. were inhibited by Ag NPs up to 13.5 ± 0.95 and 13 ± 0.70 mm. This work will open doors for the development of new antimicrobial agents using green chemistry. [ABSTRACT FROM AUTHOR]

The allelopathic effect of Callistemon viminalis's leaf extracts on seed germination and growth of Triticum aestivum and Cicer arietinum, as well as associated weeds (Anagallis arvensis, Poa annua, Lepidium didymium, and Vicia sativa), was studied. Different concentrations (2–10%) of aqueous extracts were used, and physiological parameters were measured. Higher concentrations (6–10%) significantly inhibited the germination and growth of wheat and chickpea. In pot assay, the extract did not affect shoot length, dry plant mass, chlorophyll, carotenoid, proline, protein content, stomatal conductance, photosynthetic and transpiration rate, and antioxidant enzymes in crop and various parameters of soil properties in comparison to the control. Both crops grew significantly at lower concentrations. This study suggests that extract of C. viminalis can inhibit the growth of A. arvensis and V. sativa without affecting germination, photosynthetic and biochemical properties of C. arietinum and T. aestivum, and soil properties, making it a potential candidate for bioherbicide development. [ABSTRACT FROM AUTHOR]

Callistemon viminalis belongs to the family Myrtaceae and also known as bottlebrush which is or found throughout in India. It has a remarkable place in Ayurvedic medicine of India, due to presence of phytoconstituents and pharmacological activities. Callistemon species as a farm tree are planted for forestry or ornamental purposes and for weed as well. In traditional Chinese medicines, C. viminalis is used for treating hemorrhoids. Hot drink locally 'tea' in Jamaica from C. viminalis has been used for the treatment of gastroenteritis, diarrhea and skin infections. The phytochemical research carried out on C. viminalis extracts and showed that the plant is rich in phenolics, triterpenoids, flavonoids, saponins, steroids, alkaloids, tannin, carbohydrates, amino acids and proteins compounds. The investigated pharmacological studies reported the presence of anti-inflammatory, Alzheimer, hemolytic activity, anthelmintic, anti-oxidant property, anti-bacterial, antifungal and hepatoprotective activities in C. viminalis. [ABSTRACT FROM AUTHOR]

This study aimed to examine the antibacterial effects of constituents obtained from Callistemon viminalis leaves. This goal was achieved by using three organic solvents, namely Ethanol, Ethyl acetate, and Hexane to prevent the growth of the causative urinary tract infections isolates, such as Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, and Proteus sp. in Iraq. The C. viminalis fresh leaves collected from different regions of Hillah City, during March 2020, were classified according to the taxonomic features of Iraqi Flora. Extractions were completed by a method of digestion and then the stock solution of 200 mg/mL was prepared in 10% of Dimethylsulfoxide. A Millipore filter (0.22 µm) was used for the sterilization of all the extracts used in this study. Agar well diffusion method was utilized to test the antibacterial effects of the constituents separated from the dried leaves of C. viminalis against the urinary tract infection bacteria at three concentrations of 50, 100, and 200 mg/mL for each extracted constitute by the three different solvents. Dimethylsulfoxide 10% and the meropenem were utilized as the negative and positive controls. Constituents separated by ethanol solvent at 200 mg/mL exhibited significant supremacy (P≤0.05) over the meropenem against Proteus sp. isolate, and exhibited the same significant difference (P≤0.05), compared to the meropenem drug against E. coli. Constituents extracted by Ethyl acetate organic solvent at a concentration of 200 mg/mL exhibited a similarly significant effect (P≤0.05), compared to the meropenem against Proteus sp. isolate. However, the hexane extract was the least effective among the other solvents utilized in this study. The results of the current study revealed that constituents in the leaves of C. viminalis could be considered a valuable herbal remedy for controlling urinary tract infections pathogenic bacteria.

This article reports a simple, cost-effective, and eco-friendly biosynthesis of ZnO/Fe3O4 nanocomposites using Callistemon viminalis leaves’ water extract. For the first time, we used a green synthetic route via C. viminalis leaves’ extract to prepare ZnO/Fe3O4 nanocomposites (NCs) using zinc acetate and ferric chloride as precursor materials. Fourier transform infrared (FTIR) spectroscopic results revealed polyphenolic compounds mainly phenolic acids present in the plant extract acted as both reducing and stabilizing agents to synthesize ZnO/Fe3O4 NCs. Outcomes of XRD and X-ray photoelectron spectroscopy confirmed the formation of ZnO–Fe3O4 heterojunction in ZnO/Fe3O4 NCs, with crystallite sizes of 45, 35, and 60 nm, respectively, according to Debye–Scherrer’s formula. EDX confirmed Zn, Fe, and O in the ZnO/Fe3O4 nanocomposite. Scanning electron microscopy and transmission electron microscopy (TEM) analyses revealed the existence of both ZnO and Fe3O4 in the NCs with some agglomeration. The thermal stability of NCs was evaluated using thermogravimetric analysis (TGA) and differential thermal analysis (DTA) in a nitrogen atmosphere. In addition, as-prepared ZnO/Fe3O4 NCs along with biosynthesized ZnO and Fe3O4 (prepared by C. viminalis extract) nanoparticles were examined for photodegradation of methylene blue under visible light irradiation for 150 min. The result reveals that the photodegradation efficiency of ZnO/Fe3O4 NCs (99.09%) was higher compared to that of monometallic ZnO (84.7%) and Fe3O4 (37.1%) nanoparticles.

Mosquitoes are major disease vectors, therefore keeping them under control is essential for human health. Insecticides have been shown to be effective at controlling mosquito populations, but insecticide resistance and environmental concerns are increasing. Looking for the health and environment hazards and cost of synthetic insecticides, there is a need to find a safe, practical and effective alternatives. This study aimed to determine the level of effectiveness and the presence of phytochemical analysis of Gliricidia sepium and Callistemon viminalis leaves extracts. It also included the larvicidal effect from the different extract formulations of Madre de Cacao and Bottlebrush at different instar stage of mosquito larvae. It further investigated whether there is no significant difference in the effectivity among the five different formulations of leaves extract. Results of the experiment revealed that 100% Madre de Cacao formulation were found to be very effective in killing mosquito larvae followed by 75%:25%, 50%:50%, 25%:75% while 100% Bottlebrush formulation came out as less effective. Likewise, Madre de Cacao and Bottlebrush contain sterols, flavonoids, alkaloids, saponins, glycosides, tannins and triterpene that have larvicidal impact on mosquito. Finally, a significant difference exists among the different treatments. Madre de Cacao and Bottlebrush maybe recommended as home-based mosquito larvicide which were found to be not hazardous to the health of people in extracting the leaves. A community may build and designate a certain area for plantation and development of Madre de Cacao tree and other plants that potentially source of insecticides specially mosquito larvae that can lessen the harmful effects of using commercial pesticides in controlling mosquitoes.

Callistemon viminalis, often known as the stream bottlebrush, is a tropical plant in the Myrtaceae family and is renowned for its ability to grow rapidly in riparian zones. It is exclusively found in New South Wales, Queensland, and Western Australia. The roots of this species are entangled, which helps stabilize the soil, which reduces the danger of erosion. This plant has antibacterial, antifungal, antioxidant, and other pharmacological and insecticidal abilities that are also related to other medicinal properties. This research investigates the benefits, applications, and features of several extracts obtained from components of C. viminalis (branches, flowers, fruits, bark, and leaves). Bioactive compounds were characterized in detail by noting their chemical structures. The use of C. viminalis in folk medicine was fully supported by the results. Collecting and compounding plant materials, including processing, drying, and grinding, and then doing research to screen pharmaceutical effects, are all part of making the cure. Rats had their wound healing ability tested using a method known as in vitro experimentation. This method relies on excision wounds. The capacity of the extracted substance to close wounds when applied as an ointment was shown to be greater than in the control. The epithelization time in the standard and treated groups was significantly shorter than in the basic ointment base treatment group. The group treated with 5% w/w extract ointment had greater traction intensity than the control group (1.96 gm/mm2), with a significant difference of (1.12) gm/mm2. The tensile strength of the (3.86) gm/mm2 of the 5% w/w treated group. A substantial increase in tensile strength was seen on the tenth day for both the extract level and the normal medicine. [ABSTRACT FROM AUTHOR]

This study aimed to examine the antibacterial effects of constituents obtained from Callistemon viminalis leaves. This goal was achieved by using three organic solvents, namely Ethanol, Ethyl acetate, and Hexane to prevent the growth of the causative urinary tract infections isolates, such as Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, and Proteus sp. in Iraq. The C. viminalis fresh leaves collected from different regions of Hillah City, during March 2020, were classified according to the taxonomic features of Iraqi Flora. Extractions were completed by a method of digestion and then the stock solution of 200 mg/mL was prepared in 10% of Dimethylsulfoxide. A Millipore filter (0.22 µm) was used for the sterilization of all the extracts used in this study. Agar well diffusion method was utilized to test the antibacterial effects of the constituents separated from the dried leaves of C. viminalis against the urinary tract infection bacteria at three concentrations of 50, 100, and 200 mg/mL for each extracted constitute by the three different solvents. Dimethylsulfoxide 10% and the meropenem were utilized as the negative and positive controls. Constituents separated by ethanol solvent at 200 mg/mL exhibited significant supremacy (P=0.05) over the meropenem against Proteus sp. isolate, and exhibited the same significant difference (P=0.05), compared to the meropenem drug against E. coli. Constituents extracted by Ethyl acetate organic solvent at a concentration of 200 mg/mL exhibited a similarly significant effect (P=0.05), compared to the meropenem against Proteus sp. isolate. However, the hexane extract was the least effective among the other solvents utilized in this study. The results of the current study revealed that constituents in the leaves of C. viminalis could be considered a valuable herbal remedy for controlling urinary tract infections pathogenic bacteria. [ABSTRACT FROM AUTHOR]

Callistemon viminalis (Sol. ex Gaertn.) G.Don ex Loudon) (family: Myrtaceae) is used for its medicinal properties in treating various metabolic disorders. We investigated the chemical characterization and biological screening of the n-hexane extract of C. viminalis. The total phenolic content was (37.45±7.40 mg GA.E/g D.E±S.D) and the total flavonoid content was (18.43±6.34 mg R.E/g D.E±S.D). GC-MS screening of the n-hexane extract tentatively identified 70 bioactive phytochemicals. The maximum antioxidant potential (289.99±9.01 mg T.E/g D.E±S.D) was observed via the FRAP assay. Enzyme inhibition assays revealed that n-hexane extract of C. viminalis showed enzyme inhibition against the enzymes including α-glucosidase (6.9±0.13 mmol of ACA.E/g D.E±S.D); α-amylase (7.2±0.56 mmol of ACA.E/g D.E±S.D), urease (4.95±0.9 mg of TU.E/g D.E±S.D), acetylcholinesterase (2.9±0.08 mg GALA.E/g D.E±S.D), lipoxygenase (4.93±1.05 mg of Indo.E/g D.E±S.D) and tyrosinase (4.33±0.62 mg of KA.E/g D.E±S.D). The extract showed maximum antibacterial activity against Staphylococcus aureus (71.30±4.44 %) followed by Bacillus subtilis (68.55±2.70 %), Pseudomonas aeruginosa (57.86±6.02 %), and Salmonella typhi (53.90±5.05 %). Docking studies revealed good docking interactions between ligands and the studied enzymes, whereas ADME analysis revealed the pharmacokinetic profiles of the phytoconstituents. C. viminalis possesses promising therapeutic potential and can be further explored for drug development and drug design., (© 2024 Wiley-VHCA AG, Zurich, Switzerland.)

Rhus javanica (Anacardiaceae) containing abundant glucopyranosidal constituents, is traditionally used to treat gastric and duodenal ulcer, dysentery, and diarrhea. Rumex hastatus (Polygonaceae) widely distributed in Pakistan, has traditional importance in treating wound healing, jaundice, rheumatism, and skin diseases. Callistemon viminalis (Myrtaceae), a rich source of essential oils, saponins, triterpenoids, phloroglucinols, and flavonoids is used in industries, perfumes, nutrition, and cosmetics. Taking the importance of the subject plants, this study is designed to synthesize silver nanoparticles via aqueous extracts of R. javanica (RJAgNPs), R. hastatus (RHAgNPs), and C. viminalis (CVAgNPs). Synthesis, surface, and sizes of silver nanoparticles (AgNPs) were confirmed using spectroscopic techniques including ultraviolet–visible (UV–Vis), Fourier transform-infrared (FT-IR), and scanning electron microscopy (SEM). AgNPs were produced in ratios 1:15, 1:16, and 1:9 and inferred via appearance of a sharp surface plasmon resonance (SPR) absorption peak (400–435 nm), which represented well-defined, stable, and spherical AgNPs. From SEM analysis, the sizes of RJAgNPs, RHAgNPs, and CVAgNPs were found to be 67 nm, 61 nm, and 55 nm, respectively. The synthesized AgNPs exhibited potential free radical scavenging, antibacterial, and catalytic properties in degradation of dyes including Congo red, methylene blue, methyl orange, rhodamine B, ortho and para -nitrophenols, and several food colours. Hence, the subject AgNPs in the current study might display promising role in drug development and remediation of environmental/industrial effluents. [ABSTRACT FROM AUTHOR]

Aim: The study was carried out to evaluate the neuroprotective effect of methanol extract of Callistemon viminalis in aluminium chloride induced dementia of alzheimer's type in mice. Methods: Swiss albino mice of either sex were divided into 5 groups: vehicle control; AlCl3 + normal saline; AlCl3 + rivastigmine; AlCl3+ extract (50 mg/kg; p.o); AlCl3 + extract (100 mg/kg; p.o). The following parameters were analyzed in all groups: a) Behavioral parameters- morris water maze test, b) Biochemical parameters- AchE level, GSH level, SOD level, catalase level and nitrite level. Histopathological study- Hippocampus and cerebral cortex region of mice brain. Results: The presence of various phytoconstituents like betulinic acid, ursolic acid, ß-sitosterol and lupeol reported through TLC, have a potent role as antioxidant and also known to improve blood flow as well as reduce plaque formation which proves that the extract of this plant can be used in alzheimer. Oral administration of MECV caused significant (p<0.01) decrease in escape latency time and significant (p<0.01) increase in total time in a dose dependent manner as compared to the aluminium chloride treated group. Additionally, post treatment with MECV (50mg/kg and 100 mg/kg) showed significant (p<0.01) decrease in AchE and nitrite level and significant (p<0.01) increase in the GSH, catalase and SOD level in mice brain. The histopathology of hippocampus and cerebral cortex of mice brain showed that the toxicity induced by the aluminium chloride was markedly reduced by the MECV. The normal histoarchitecture pattern of the hippocampus and cerebral cortex was also preserved. Conclusion: The evidence regarding the presence of phytoconstituents and analytical studies confirming their presence, along with preclinical studies on mice with conclusive results in treatment of Alzheimer shown by the extract concludes that the extract exhibits neuroprotective effect. [ABSTRACT FROM AUTHOR]

Background and aims: Urinary tract infection is considered as one of the most common clinical problems in the world. The aim of this study was to investigate the interaction effects of pharmaceutical and antibacterial activity of methanol extracts of Callistemon viminalis on a number of bacteria that cause urinary tract infections.Methods: In this experimental research, after drying leaves, extracts were prepared using methanol. The minimum lethal activity of 500, 250 and 125 µg/ml concentrations of the extracts on the standard bacteria was tested using disk diffusion and dilution method. In order to study the synergistic and antagonistic effect, a standard strains of bacteria was cultured on the medium containing methanol extract and then antibiotic discs were put on it.Results: According to the results of disk diffusion test in Agar, the highest inhibition zone diameter in 500 µg/ml was related to Staphylococcus epidermidis and the minimum diameter in this concentration was related to E. coli. Study MIC results was showed that the extract of Callistemon viminalis has the highest inhibitory effect on Staphylococcus saprophyticus and epidermidis. The extracts of Callistemon viminalis showed synergistic effects with vancomycine and ciprofloxacin on Staphylococcus aureus and epidermidis, Proteus vulgaris and Klebsiella pneumoniae.Conclusion: The results of this study indicate that extracts of Callistemon viminalis , alone or in combination with antibacterial agents may be useful in treatment of urinary tract infections. Additionally, this component can enhance the effect of some antibiotics; this implies its application, especially in drug resistance cases.

Background & Objective: The emergence of fungal drug-resistance and also different side- effects related to the currently available drugs has led to a high demand for novel antifungal drugs. The purpose of this study was to evaluate the inhibitory activity of methanolic and aquatic extracts of Callistemon viminalison on the growth of Candida albicans in vitro. Materials & Methods: Having dried the leaves, the researchers prepared the extracts by distillation using methanol and water. The minimum lethal activity of 500, 250 and 125 µg/ml concentrations of the extracts on the yeast C.albicans was tested using disk diffusion and dilution method. In order to study the synergistic effect, a standard strain of C. albicans was cultured on medium containing methanol extract and then amphotericin B discs were put on it. Results: Based on the results, the antifungal activity of Callistemon viminalis methanol extract on C.albicans was more than the aqueous extract. In considering the Minimum Inhibitory Concentration (MIC), the methanol extract of the Callistemon viminalis at a concentration of 62.5μg/ml and the aqueous extract at a concentration of 250μg/ml inhibitory effect on C. albicans. The inhibition zone diameter of amphotericin B was 18mm and should be combined with Callistemon viminalis methanol extract at a concentration of 62.5μg/ml was 21mm, and also in combination with the aqueous extract at a concentration 250μg/ml it was 19 mm. Conclusion: Although amphotericin B is the most effective drug for treating systemic fungal infections, its effect will increases when combined with Callistemon viminalis extracts.

Objective: To isolate and identify the compounds in the essential oils from the leaves of Callistemon viminalis (D.R.) and Melaleuca leucadendron (Linn.) collected in Dakar, Senegal. Methods: The essential oils from the leaves of these two myrtaceaes were extracted by steam distillation and analyzed by gas chromatograph and gas chromatography–mass spectrometer. Results: A total of 34 constituents were identified in the oil of Callistemon viminalis and the major compounds were 1.8-cineole (58.12%), limonene (9.72%), α-terpineol (9.56%), geranial (6.02%), δ-elemene (3.53%), myrcene (2.96%) and α-pinene (2.49%). For the essential oil of Melaleuca leucadendron, 43 constituents were identified, and 1.8-cineole (28.87%), epiglobulol (23.06%), α-pinene (12.22%), limonene (11.65%) and α-terpineol (7.06%) were major compounds. Conclusions: Considering properties of the identified major compounds, essential oils of both studied myrtaceae could be used in the medicine field including the food, pharmaceutical and cosmetic industry.

Two new polyketide metabolites, the 12-membered macrolides 4-hydroxy-12-methyloxacyclododecane-2,5,6-trione (1) and 12-methyloxacyclododecane-2,5,6-trione (2), were isolated from the endophytic fungal strain Cladosprium colocasiae A801 of the plant Callistemon viminalis, together with five known derivatives. Their structures were fully characterized by means of detailed spectroscopic analysis for new structures, and in comparison with published data for known compounds. The antibacterial, cytotoxic, and α-glucosidase inhibitory activities of the new compounds 1 and 2 were evaluated. [ABSTRACT FROM AUTHOR]

Three bacterial isolates were isolated from infected potato tubers showing soft and brown rots like symptoms as well as one isolate from infected peach tree showing crown gall symptom. The morphological, biochemical and molecular assays proved that bacterial isolates belonging to Pectobacterium carotovorum subsp. carotovorum , Ralstonia solanacearum , Dickeya spp. and Agrobacterium tumefaciens . The acetone (AcE) and n -butanol (ButE) extracts of Callistemon viminalis flowers and essential oil from aerial parts of Conyza dioscoridis as well as ButE of Eucalyptus camaldulensis bark are evaluated at different concentrations against the growth of the isolated bacteria. The diameter of inhibition zone (IZ) and the minimum inhibitory concentrations (MICs) are compared. Results indicated that the highest IZ values were 20.0 mm and 18.3 mm for E. camaldulensis bark ButE and C. viminalis flower ButE, respectively, against P. carotovorum ; 16.3 mm and 16.0 mm for E. camaldulensis bark ButE and C. viminalis flower ButE, respectively, against R. solanacearum ; 18.5 mm for C. viminalis flower AcE and C. dioscoridis aerial parts EO against Dickeya spp.; and 15.0 mm for C. viminalis flower AcE against A. tumefaciens . MICs ranged from <16 μg/mL for D. solani to >4000 μg/mL for A. tumefaciens . It was proved that C. viminalis flowers AcE contains mainly 5-hydroxymethylfurfural (20.6%), palmitic acid (18.5%), and pyrogallol (16.4%); while C. viminalis flower ButE contains palmitic acid (36.3%), 2-hydroxymyristic acid (9.4%), 5-hydroxymethylfurfural (7.2%), and shikimic acid (6.6%); whereas E. camaldulensis bark ButE contains 8-nonynoic acid methyl ester (45.6), camphor (30.9%), menthol (8.8%), and 1,8-cineole (eucalyptol) (8.2%), whilst the EO of C. dioscoridis aerial parts comprises Z -(13,14-epoxy)tetradec-11-en-1-ol acetate (11.6%), γ -elemene (10.2%), tau.-muurolol (7.1%), and cadina-3,9-diene (4.7%). It can be concluded that phytochemical extracts of C. viminalis , E. camaldulensis and C. dioscoridis demonstrated strong to moderate antibacterial effects against the studied plant bacterial pathogens. [ABSTRACT FROM AUTHOR]

Experimental studies were carried out under invitro conditions to examine the effect of Callistemon viminalis essential oil (EO) against the Echinochloa crus-galli L., Amaranthus viridis and Phalaris minor. EO composition was analysed by gas chromatography/mass spectrometry, revealing that EO was rich in monoterpenes and sesquiterpenes like eucalyptol, D-limonene, α-terpineol and caryophyllene oxide. EO applied in the concentration range of 0.5, 1, 2 and 4 μl against Amaranthus viridis, Echinochloa crus-galli L. and Phalaris minor drastically affected the germination of all test plants and inhibited root and shoot development. Also, not only seedling growth, even the chlorophyll content also reduced appreciably. This led to the demonstration that Callistemon viminalis EO was negatively affecting the photosynthetic process. Upregulation of antioxidant enzymes activities indicated that these enzymes were providing protection against Callistemon viminalis EO induced stress. Amaranthus viridis was reported to be more sensitive in comparison to Echinochloa crus-galli L. and Phalaris minor. [ABSTRACT FROM AUTHOR]

Objective To isolate and identify the compounds in the essential oils from the leaves of Callistemon viminalis (D.R.) and Melaleuca leucadendron (Linn.) collected in Dakar, Senegal. Methods The essential oils from the leaves of these two myrtaceaes were extracted by steam distillation and analyzed by gas chromatograph and gas chromatography–mass spectrometer. Results A total of 34 constituents were identified in the oil of Callistemon viminalis and the major compounds were 1.8-cineole (58.12%), limonene (9.72%), α-terpineol (9.56%), geranial (6.02%), δ-elemene (3.53%), myrcene (2.96%) and α-pinene (2.49%). For the essential oil of Melaleuca leucadendron , 43 constituents were identified, and 1.8-cineole (28.87%), epiglobulol (23.06%), α-pinene (12.22%), limonene (11.65%) and α-terpineol (7.06%) were major compounds. Conclusions Considering properties of the identified major compounds, essential oils of both studied myrtaceae could be used in the medicine field including the food, pharmaceutical and cosmetic industry. [ABSTRACT FROM AUTHOR]

Background & Objective: The emergence of fungal drug-resistance and also different side- effects related to the currently available drugs has led to a high demand for novel antifungal drugs. The purpose of this study was to evaluate the inhibitory activity of methanolic and aquatic extracts of Callistemon viminalison on the growth of Candida albicans in vitro. Materials & Methods: Having dried the leaves, the researchers prepared the extracts by distillation using methanol and water. The minimum lethal activity of 500, 250 and 125 µg/ml concentrations of the extracts on the yeast C.albicans was tested using disk diffusion and dilution method. In order to study the synergistic effect, a standard strain of C. albicans was cultured on medium containing methanol extract and then amphotericin B discs were put on it. Results: Based on the results, the antifungal activity of Callistemon viminalis methanol extract on C.albicans was more than the aqueous extract. In considering the Minimum Inhibitory Concentration (MIC), the methanol extract of the Callistemon viminalis at a concentration of 62.5μg/ml and the aqueous extract at a concentration of 250μg/ml inhibitory effect on C. albicans. The inhibition zone diameter of amphotericin B was 18mm and should be combined with Callistemon viminalis methanol extract at a concentration of 62.5μg/ml was 21mm, and also in combination with the aqueous extract at a concentration 250μg/ml it was 19 mm. Conclusion: Although amphotericin B is the most effective drug for treating systemic fungal infections, its effect will increases when combined with Callistemon viminalis extracts. [ABSTRACT FROM AUTHOR]

Callistemon viminalis ( C. viminalis ) is a plant that has been reported to have various medicinal values such as antibacterial, antifungal, antioxidant activities and other pharmaceutical and insecticidal properties. This review covers the potentials, applications and properties of different extracts from different parts (branches, flowers, fruits, bark, leaves) of C. viminalis . Furthermore, the chemical structures of the bioactive compounds were reported for biological activities. All the results supported the traditional uses of C. viminalis in folk medicine. In addition, some researches supported the use of C. viminalis extracts for the preparation of metal oxide nanoparticles. [ABSTRACT FROM AUTHOR]

O presente trabalho teve como objetivo determinar a composição química e avaliar a atividade antimicrobiana dos óleos essenciais obtidos das folhas (frescas e secas) e flores da Callistemon viminalis. Os óleos essenciais foram analisados por CG/EM. A concentração inibitória mínima (CIM) foi determinada utilizando o método de microdiluição em caldo frente a bactérias Gram-positivas e Gram-negativas. De um total de 96,72%, 98,70% dos compostos identificados nos óleos essenciais foram monoterpenos. O 1,8-cineol foi o componente majoritário no óleo essencial das folhas frescas (70,43%), folhas secas (71,71%) e flores (42,39%), seguido do tricicleno com 12,97% nas folhas frescas, 8,20% nas folhas secas e 28,08% nas flores. A CIM para todos os micro-organismos testados foi ≥ a 2.000 μg/mL. Esse estudo é o primeiro relato sobre a composição química e atividade antimicrobiana do óleo essencial das flores de C. viminalis.

The chemical composition and the antibacterial activity of the essential oils obtained by hydrodistillation from the leaves of Callistemon citrinus and Callistemon viminalis were analyzed by GC and GC/MS. Twenty-four and twelve components were identified for C. citrinus and C. viminalis, representing 92.0% and 98.3% of the total oils. The major components of C. citrinus and C. viminalis were 1,8-cineole (61.2% and 83.2%) and α-pinene (13.4% and 6.4%), respectively. The in vitro antibacterial activity of the essential oils was studied against 12 bacteria strains using disc diffusion and broth microdilution methods. The oils exhibited strong zone of inhibitions against some bacteria such as S. faecalis (20.3-24.0 mm), both strains of S. aureus (23.0-26.3 mm), B. cereus (17.3-19.0 mm) and S. macrcesens (11.3-23.7 mm) when compared to standard antibiotics gentamycin and tetracycline used as controls. Expect for P. aeruginosa and S. macrcescens, the MIC values of both essential oils ranged from 0.31-2.50 mg/mL.

The essential oils of natural origin possess antimicrobial activity. These oils are formulated in different nanocarriers in order to improve bioavailability and antimicrobial efficacy in several topical ailments. Essential oils have been used in acne therapy. This study aims to extract Callistemon viminalis leaf oil, their constituent's identification and preparation of nanoemulsion loaded gel. Essential oil extraction was carried out using Clevenger apparatus (hydro-distillation method). The identification of different components of oil was done by Gas Chromatography-Mass Spectrometry. Nanoemulsion was prepared by spontaneous emulsification method using Tween 80 and Chremphor EL. The prepared nanoemulsion formulations were evaluated for globule size, polydispersity index using Zetasizer (Malvern). The optimized nanoemulsion formulations were further loaded in Carbopol gel and evaluated for rheological behaviour (Modular Compact Rheometer, MCR 102e, Anton Paar) and antimicrobial activity. The optimized nanoemulsion of essential oil (Callistemon viminalis) was found in the nano-range (21.46±2.23 nm) with narrow polydispersity index (0.282±0.052). The nanoemulsion loaded gel possesses good rheological properties for topical application. Callistemon viminalis oil nanoemulsion-loaded gel possesses antimicrobial potential against acne bacteria's and hence it would be better choice in acne management. [ABSTRACT FROM AUTHOR]

Phytoconstituents of the peels of Callistemon viminalis has been investigated for the first time. As a result, two pair of diastereomers of hybrids of β-triketone and α-phellandrene, named viminalisones A-B (1 – 2) and viminalisones C D (3 – 4), and three known analogues were obtained. Their structures and absolute configurations were elucidated through a combination of the analysis of their MS data, NMR spectra, single-crystal X-ray diffraction, and their experimental and calculated electronic circular dichroism (ECD) spectra. All isolates were evaluated for their antimicrobial activities against Botrytis cinerea and Cutibacterium acnes. Meroterpenoid 7 exhibited antibacterial activity against Botrytis cinerea with a MIC value of 0.256 mg/mL. [Display omitted] • Four new hybrids of β-triketone and α-phellandrene, viminalisones A-D (1 – 4), were isolated from the peels of C. viminalis. • Their absolute stereochemistry was determined by ECD spectra calculations and single-crystal X-ray diffraction. • Viminalisones A and B (1 and 2) and viminalisones C and D (3 and 4) are two pairs of epimers, respectively. • Compound 7 exhibited antibacterial activity against Botrytis cinerea with a MIC value of 0.256 mg/mL. [ABSTRACT FROM AUTHOR]

Viminalins A-O ( 1 – 15 ), a series of new [3+2] hybrids of acylphloroglucinols and α -phellandrene featured a 2,3-dihydrobenzofuran core were isolated from the fruits of Callistemon viminalis . Their structures were established on the basis of extensive analysis of NMR spectra, circular dichroism, and X-ray crystallography. An oxidative [3+2] cycloaddition between acylphloroglucinol and monoterpene was speculated as the key step in the biosynthetic pathway. Bioactivities screen indicated that compound 6 exhibited moderate cytotoxic activity. [ABSTRACT FROM AUTHOR]

Callviminols A-E ( 1 – 5 ), five rare phloroglucinols bearing a framework embodying a hexahydrodibenzo[ b , d ]furan or 2-phenylcyclohexanol nucleus derived from a phloroglucinol-monoterpene adduct, were isolated from the leaves of Callistemon viminalis . Their structures were established via extensive spectroscopic measurements, with the absolute configuration of 5 determined by electronic circular dichroism (ECD) calculations. The plausible biogenetic pathway suggested that a unique oxidative radical addition and classic cationic cyclization were key biosynthetic steps. [ABSTRACT FROM AUTHOR]

Callistiviminenes A-O, fifteen adducts of β-triketone with sesqui- or monoterpene, along with a known compound, were isolated from the fruits of Callistemon viminalis . Callistiviminenes A and B are β-triketone-coupled (−)-bicyclosequiphellandrene contained an oxaspiro[5.5]undecene unit, and callistiviminenes C-E are rare adducts of β-triketone and bicyclogermacrene. Their structures and absolute configurations were elucidated by spectroscopic and computational methods, as well as by single-crystal X-ray diffraction experiment. A plausible biosynthetic pathway to these compounds involves a hetero-Diels–Alder reaction. Callistiviminenes C and D exhibited inhibition against lipopolysaccharide-induced nitric oxide production in RAW 264.7 macrophages with IC 50 value of 20.3 μ M and 32.5 μ M, respectively. [ABSTRACT FROM AUTHOR]

A phytochemical study on the leaves of Callistemon viminalis, a widely distributed ornamental and medicinal plant of agricultural importance in China, resulted in the isolation of eleven acylphloroglucinols, including six new ones named callistenones F-K (1-6), as well as five known congeners. Their structures were fully characterized using spectral data interpretation for the new structures and compared to published data for the known ones. All the isolated compounds were evaluated for in vitro antimicrobial activity and growth inhibitory activity against four tumor cell lines (MCF-7, NCI-H460, SF-268 and HepG-2). [ABSTRACT FROM AUTHOR]

Green methods are powerful tools to minimize the use of toxic chemicals which are harmful to human beings as well as environment. The present study focuses on the use of aqueous extract ofCallistemon viminalis(bottlebrush) leaves for the synthesis of silver nanoparticles. The extract was used as a bioreductant and the polyphenols and flavanoids present in extract are responsible for the reduction of Ag+ions to zero valent silver nanoparticles. The effect of concentration of Ag+ions and cetyltrimethylammonium bromide on the nanoparticles was examined. On increasing the concentration of stabilizer, different morphological nano-couples are formed. The successful formation of silver nanoparticles was demonstrated by using ultraviolet–visible, transmission electron microscope and scanning electron microscope. Transmission electron microscope image analysis showed wide size distribution having dimer nanoparticles of hexagonal-triangular, square-triangular, spherical-triangular, spherical-spherical square-spherical morphologies. The antibacterial activity of extract reduced silver nanoparticles against four strains viz.Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniaeandSalmonella typhimuriumwas evaluated by calculation of minimum inhibitory concentration and minimum bactericidal concentration. The results show that synthesized nanoparticles could inhibit the growth of various bacteria tested. [ABSTRACT FROM AUTHOR]

In this contribution, it is demonstrated for the first time in the literature the possibility of synthesizing Sm 2 O 3 nano-scaled particles as small as 〈ϕ particles 〉 ∼21.9 ± 5 nm using an entirely new green process. This latter is based on the usage of natural extract of the Callistemon viminalis as a strong chelating agent at room temperature. The selected area electron diffraction and the high resolution transmission electron microscopy confirmed the polycrystallinity of the Sm 2 O 3 nano-particles upon annealing at 500 °C. The complementary investigations by X-rays diffraction, infrared, Raman and X-rays photoelectron spectroscopy substantiated the single phase and the elemental purity of the Sm 2 O 3 nano-particles. [ABSTRACT FROM AUTHOR]

Methanol extracts of Callistemon viminalis (Sol. Ex Gaertner) G.Don Ex Loudon fruits, bark and leaves were tested for molluscicidal activity. Snails were collected and kept in dechlorinated water under standard condition. Ten adults Biomphalaria alexandrina, of the same size, were introduced in plastic acquaria for each experiment. The fruits, barks and leaves were extracted with methanol and the methanol extracts were kept for testing as molluscicides. Different extracts proved to have molluscicidal activity against the vector of schistosomiasis, B. alexandrina snails. LC50 values for C. viminalis fruits, bark and leaves were 6.2, 32 and 40 ppm respectively. The C. viminalis fruits extract showed the highest effect against the tested snails. Histopathological studies proved that the site of action of all tested extracts was localized in the digestive system and hermaphrodite gland. [ABSTRACT FROM AUTHOR]